Basic mechanisms of the secretory process are studied in cells of the rat pancreas, salivary and lacrimal glands. Techniques utilized include light and electron microscopy, cytochemistry, radioautography, and basic biochemical procedures. Major areas of investigation are: (1) the structure and function of the Golgi apparatus and GERL; (2) experimental pathology and lysosome function in salivary glands; (3) structure and permeability properties of junctional complexes in the rat parotid gland; and (4) the effects of sialographic procedures on the structure of the rat submandibular gland.